Stabilizer systems for light-curable polyesters

ABSTRACT

A stabilized composition curable by U.V. light, comprising an unsaturated polyester resin, a benzoin ether of a primary alcohol, a copper compound soluble in the polyester resin and at least one organic compound having ionically-bound chlorine or capable of forming chlorine ions in situ.

United States Patent [191 Roskott et a1.

STABILIZER SYSTEMS FOR LIGHT-CURABLE POLYESTERS Inventors: Lodweiik Roskott, Deventer;

Arnoldus Adrianus Maria Groenendaal, Vorden; Hans Jaspers, Diepenveen, all of Netherlands Assignee: Akzo N.V., Arnhem, Netherlands Filed: Jan. 31, 1973 Appl. No.: 328,438

Foreign Application Priority Data Feb. 4. 1972 Netherlands 7201453 US. Cl. 204/159.19, 204/l59.l5, 204/l59.2 B, 260/28, 260/285 R, 260/41 A, 260/41 B, 260/4575 C, 260/458 N, 260/459,

Int. Cl ..B01j 1/10, B0lj l/l2 Field of Search 260/4595 C, 45.9, 861,

[ June 25, 1974 260/863, 864, 45.75 R, l59.15; 204/l59.l9

[56] References Cited UNITED STATES PATENTS 3,188,363 6/1965 Amidon et al. 260/4575 C 3,627,657 12/l97l Nistri et al 204/l59.l5

Primary Examiner-Murray Tillman Assistant Examiner-Richard B. Turer Attorney, Agent, or FirmStevens, Davis, Miller &

Mosher [5 7] ABSTRACT 17 Claims, N0 Drawings STABILIZER SYSTEMS FOR LIGHT -CURABLE POLYESTERS The present invention relates to a process for the preparation of a stabilized composition which is curable by U.V. light, to the composition per se and also to the curing of this composition.

The present invention relates to a process for the preparation of a stabilized, U.V. light curable composition, which comprises an unsaturated polyester resin, a benzoin ether of a primary alcohol and a copper compound which is soluble in the resin. After curing the composition by U.V. light a polyester has been obtained suitable for e.g., surface coatings.

The expression unsaturated polyester resin" as used herein means a mixture of an unsaturated polyester and one or more polymerizable ethylenically-unsaturated monomers, such as styrene, vinyl toluene, methylmethacrylate, diallyl phthalate, divinyl benzene, p-tert.butylbenzene and vinyl acetate. Reference is made to US. Pat. No. 3,367,994.

The weight ratio of monomer to unsaturated polyester generally ranges from 30-50 parts of monomer to 70-50 parts of polyester.

The unsaturated polyester may be obtained by reacting a polyhydric alcohol, such as ethylene glycol, propylene glycol or diethylene glycol, with an unsaturated dibasic carboxylic acid, such as maleic acid, fumaric acid or itaconic acid, if desired in the presence of a saturated acid, such as malonic acid, adipic acid, sebacic acid or tartaric acid, and also phthalic acid, isophthalic acid or tetrachlorophthalic acid.

In order to prevent the unsaturated polyester resin from undergoing premature gelation, a stabilizer is desirably added to the polyester in a quantity of 0.005 0.15 percent by weight, preferably 0.01 percent by weight calculated on the unsaturated polyester. The stabilizers hitherto most used are hydroquinone and p.tert.-butylcatechl. Unsaturated polyester resins may be cured with the aid of U.V. irradiation. For rapid curing, photoinitiators are incorporated in the unsaturated polyester resin in an amount of 0. l 5 percent, preferably l 2 percent by weight calculated on the polyester resin. The preferred photo-initiators are benzoin ethers derived from primary alcohols, such as methyl alcohol and ethyl alcohol, propyl alcohol, n-butyl alcohol, isobutyl alcohol and 2-ethylhexyl-alcohol.

However, unsaturated polyester resins containing benzoin ethers derived from primary alcohols as photoinitiators have the disadvantage that they gel prematurely on storage in the dark. In German Auslegeschrift No. 1,902,930 a copper compound which is soluble in the resin is recommended for incorporation in the polyester resin, in addition to the primary alcohol benzoin ether and the usual stabilizer. Suitable copper compounds are copper acetate, copper laurate, copper ethylene diamine triacetate, copper citrate, copper benzoate and, particularly, copper naphthenate, copper stearate, copper octoate and copper acetylacetonate. The copper compounds are incorporated in the resin in an amount of 0.00001 0.001% preferably 0.0001 0.0002 percent by weight of copper, calculated on the polyester resin.

It has now been found that a composition having a surprisingly good storage stability in the dark may be obtained by incorporating as a stabilizer an organic compound which either contains ionically bound chlorine or is capable of forming chlorine ions in situ, in an U.V. light curable composition comprising an unsaturated polyester resin, a benzoin ether of a primary alcohol as a photo-initiator and a copper compound soluble in the resin. Further, it has been found that the rate of curing is not affected unfavorably by curing the resin with U.V. light. Organic chlorine-containing compounds, such as tri-alkylbenzyl ammonium chloride, are known to be suitable for use as stabilizers for polyester resins. However, it was not known that the combination of these compounds with copper compounds as a stabilizer for U.V. light curable polyester resins has a stabilizing effect greater than might be expected from each of the compounds alone.

Quaternary ammonium chlorides such as C -C -alkyldimethylbenzyl ammonium chloride, C C -alkyldimethylethylbenzyl ammonium chloride, phenyltrimethyl ammonium chloride, stearyldimethylbenzyl ammonium chloride, alkylmethylisoquinolinium chloride, di-alkyldimethyl ammonium chloride, and salts of amines with hydrochloric acid, such as dimethylamine.HCl, benzylamine.HCl and triethylamine.HCl may be mentioned as examples of organic compounds which contain ionically bound chlorine ions. Compounds having the general formula:

wherein R represents an alkyl group, C5-C2), Or a substituted or non-substituted aryl group, of C C R is a substituted or non-substituted aryl group, C C and R represents a hydrogen atom or an alkyl group, C -C such as lauroyl chloride, 2-ethylhexanoyl chloride, ortho-methylbenzoyl chloride, benzoyl chloride and cumyl chloride, may be mentioned as examples of organic compounds capable of forming chlorine ions in situ. It has been found that those organic chlorine compounds which cause a precipitate of silver chloride, when 0.1 to 1.0 g of the compound is dissolved in about 10 ml of a mixture of water and acetone in a ratio of 4:1 to 1:1 followed by the addition of about 0.5 ml of 4N nitric acid and a few drops of 0. IN silver nitrate, are capable of forming chlorine ions in situ in a polyester resin. Dependent upon the nature of the resin and the copper compound used, 0.001 0.1 percent and, preferably 0.01 0.05 percent, by weight, of stabilizer according to the present invention, calculated on the polyester resin, may be incorporated in the resin.

If desired, fillers, such as calcium carbonate, calcium magnesium carbonate, magnesium silicate, silicon oxide, aluminum silicate, barium sulphate, or calcium sulphate, may be added to the polyester resin so as to formulate it for use as a putty, in an amount of 5-500 percent and preferably 25-250 percent by weight, calculated on the polyester resin. in order to prevent airinhibition, 0.1 percent by weight of a solid paraffin having a melting point of 5254 C. may be added to resins which do not contain fillers. The composition according to the present invention may be cured in the usual way. To this end, the composition according to the present invention was spread by means of a film drawing knife on a glass plate in layers having a thickness of 300 t. Subsequently, these layers were irradiated for sec. with an U.V. light source placed 20 cm above the resin sheets. The light source had a light emission mainly in the range from 300 to 400 millimicrons. The curing was determined with an oscillation hardness measuring apparatus according to Persoz.

hol, 0.0002 parts by weight of copper in the form of a copper naphthenate or copper octoate and a certain quantity by weight of a stabilizer according to the present invention were added to 100 parts by weight of the The curing of putties was determined with the aid of 5 unsaturated polyester resin hereinbefore described. the residual styrene-content of the resin cured accord The stability in the dark at 100 C. and the hardness acing to the method described in Kunststoffe." 53 cording to Persoz of the composition thus obtained 80l-804 (1963). The storage stability of the unsatuwere determined. Comparable tests were made with a rated resin was determined in the dark at a temperature polyester resin containing a benzoln ether of a primary of 100 C. 10 alcohol, no copper or solely copper or a stabillzer ac- The present invention will be illustrated by the folcording to the present invention. The results obtained lowing Examples which are by no means limitative. 1n are tabulated hereafter in Table 1.

these Exam les where reference is made to an unsatu- P EXAMPLE 11 rated polyester resin, this refers to an all-purpose composition obtained by condensing 1 mol of maleic acid 15 2 parts by weight of n-butyl ether of benzom, 0.0002 anhydride and 1 mol of phthalic acid anhydride with parts by weight of copper in the form of copper naph- 1.1 mol of ethylene glycol and 1.1 to 1.2 mol of propathenate or copper octoate, a stabilizer according to the nediol-l,2. The esteritication took place at a temperapresent lnventlon and a filler were added to 100 parts ture of 200 C. while stirring and under a current of niby weight of the unsaturated polyester resin hereinbetrogen. After the addition of 0.01 part by weight of hyfore described. The stability in the dark at 100 C. and droquinone to 100 parts by weight condensate, the latthe residual styrene-content after curing of the compoter was mixed with styrene in a ratio of 65:35. The unsition thus obtained were determined. Comparable saturated polyester resin thus obtained had an acid [@515 were made with a composltlon contamlflg P ly number of about 50. ter resin, a filler and n-butyl ether of benzoin, with a composition containing in addition copper, and with a EXAM composition containing instead of copper a stabilizer PLE I according to the present invention. The results ob- 2 parts by weight of benzoin ether of a primary alcotained are tabulated hereafter In Table 2.

Table 1 stability hardness according to 70 by in min. Persoz after lighting Benzoin ether copper weight stabilizer at 100C. for 2 minutes n-butyl 250 n-butyl 80 230 n-butyl 0.05 trialkylbenzyl ammonium chloride* 53 263 n-butyl 0.05 trialkylbenzyl ammonium chloride* 308 260 n-butyl 0.013 ethylene diamine.HCl 120 258 n-butyl 0.02 cumyl chloride 32 268 n-butyl 0.02 cumyl chloride 190 260 n-ethyl 32 268 n-ethyl 65 268 n-ethyl 0.01 dimethyl-amine. HCl 27 268 n-ethyl 0.01 dimethyl-amine.HC1 164 269 n-propyl 30 272 n-propyl 1 15 256 n-propyl 0.02 o-methylbenzoyl chloride 39 276 n-propyl 0.02 o-methylbenzoyl chloride 184 269 mixture of 40% of dodecyldimethylbenzyl ammonium chloride of tetradecyldimethylbenzyl ammonium chloride 10% of hexadecyldimethylbenzyl ammonium chloride Table 2 residual styrene benzoinw stability content after n-butyl copby by in min. lighting for ether per weight filler weight stabilizer at C. 2 minutes calcium carbonate 10 0.091 150 calcium carbonate 12 0.95 150 Calcium carbonate 0.05 trialkylbenzylamm.chloride* 14 0.81 150 calcium carbonate 0.05 trialkylhenzylamm.chloride 21 0.83 50 aluminium silicate l2 0.97 50 aluminium silicate l8 1.02 50 aluminium silicate 0.05 trialklbenzylamm.chloride* 27 0.91 50 aluminium silicate 0.05 trialklbenzylamm.chloride* 52 0.90 50 aluminium silicate 0.05 phenyltrimethylamm.chloride 25 0.92

m Table 2.Cntinued residual styrene benzomstability content after n-butyl copby Fr by in min. lighting for ether per weight filler weight stabilizer at 100C. 2 minutes 50 aluminium silicate 0.05 phenyltrimethyl amm.chloride 50 0.92

+ 50 aluminium silicate 0.05 stearyldimethylbenzylamm-chloride 0.94 23 50 aluminium silicate 0.05 stearyldimethylbenzylamm-chloride 0.91 c 48 50 aluminium silicate 0.05 alkylmethylisoquinolinium chloride** 26 0.95 50 aluminium silicate 0.05 alkylmethylisoquinolinium chloride 55 0.93 150 calcium carbonate 0.05 phenyltrimethyl ammonium chloride 14 0.83 150 calcium carbonate 0.05 phenyltrimethyl ammonium chloride 0.85 150 calcium carbonate 0.05 stearyldimethyh bergylamm'chlogle I50 calcium carbonate 0.05 stearyldimethylbenzylamm-chlon'de 22 'mixlure of 40% of dodecyldimcthylbenzyl ammonium chloride 50% of tctradecyldimcthylbenzyl ammonium chloride l07( of he xacle cyldin et hylbenzyl ammonium chloride mixture of 25% dodecylmethylisoquinolinium chloride 55% tetradecylmethylisoquinolinium chloride 17% hexadecylmethylisoquinolinium chloride What is claimed is:

l. A process for preparing a stabilized, U.V. light curable composition comprising forming a mixture containing 0.1-5 percent by weight of a benzoin ether of a primary alcohol, 0.00001-0001 percent by weight of a soluble copper compound, 0.001-01 percent by weight as a stabilizer of an organic chloro compound selected from the group consisting of (a) quaternary ammonium chlorides, (b) amine hydrochlorides and (c) compounds capable of forming chlorine ions in situ and the remainder an unsaturated polyester resin, said percentages by weight being calculated on the polyester TSll'l.

2. The process according to claim 1, in which the composition contains 1 2 percent by weight of benzoin ether calculated on the polyester resin.

3. The process according to claim 1, in which the composition contains 0.0001 0.0002 percent by weight of copper calculated on the polyester resin.

4. The process according to claim 1, in which the composition contains 0.01 0.05 percent by weight of organic chloro compound.

5. The process according to claim 1, in which the stabilizer is a quaternary ammonium compound.

6. The process according to claim 1, in which the stabilizer is a salt of an amine and hydrogen chloride.

7. The process according to claim 1, in which the stabilizer is a compound having the general formula:

wherein R represents an alkyl group, C C or a substituted or nonsubstituted aryl group, C -C, R is a substituted or non-substituted aryl group, C C and R stands for hydrogen or an alkyl group, C -C 8. The process according to claim 1, wherein the copper compound is copper naphthenate or copper octoate.

9. The process according to claim 1, containing one or more fillers in an amount of 5 500 percent by weight, calculated on the polyester resin.

10. A composition curable by U.V. light comprising 0. l5 percent by weight of a benzoin ether of a primary alcohol, 0.0000l0.001 percent by weight of a soluble copper compound, 0.00l0.1 percent by weight as a stabilizer of an organic chloro compound selected from the group consisting of (a) quaternary ammonium chlorides, (b) amine hydrochlorides and (0) compounds capable of forming chlorine ions in situ and the remainder an unsaturated polyester resin, said percentages by weight being calculated on the polyester resin.

11. The composition as claimed in claim 10, which includes a quaternary ammonium compound.

12. The composition as claimed in claim 10, which includes a salt of an amine and hydrogen chloride.

13. The composition as claimed in claim 10, which includes a compound having the general formula:

I! i RC or Rho-c1 01 R2 7 8 15. The composition as claimed in claim 10, in which percent by weight calculated on the polyester resin. the copper compound is copper naphthenate or copper 17. A process for curing unsaturated polyester resins, octoate. comprising irradiating with UV. light the composition 16. The composition as claimed in claim 10, containof claim 10.

ing in addition at least one filler in an amount of 500 5 

2. The process according to claim 1, in which the composition contains 1 - 2 percent by weight of benzoin ether calculated on the polyester resin.
 3. The process according to claim 1, in which the composition contains 0.0001 - 0.0002 percent by weight of copper calculated on the polyester resin.
 4. The process according to claim 1, in which the composition contains 0.01 - 0.05 percent by weight of organic chloro compound.
 5. The process according to claim 1, in which the stabilizer is a quaternary ammonium compound.
 6. The process according to claim 1, in which the stabilizer is a salt of an amine and hydrogen chloride.
 7. The process according to claim 1, in which the stabilizer is a compound having the general formula:
 8. The process according to claim 1, wherein the copper compound is copper naphthenate or copper octoate.
 9. The process according to claim 1, containing one or more fillers in an amount of 5 - 500 percent by weight, calculated on the polyester resin.
 10. A composition curable by U.V. light comprising 0.1-5 percent by weight of a benzoin ether of a primary alcohol, 0.00001-0.001 percent by weight of a soluble copper compound, 0.001-0.1 percent by weight as a stabilizer of an organic chloro compound selected from the group consisting of (a) quaternary ammonium chlorides, (b) amine hydrochlorides and (c) compounds capable of forming chlorine ions in situ and the remainder an unsaturated polyester resin, said percentages by weight being calculated on the polyester resin.
 11. The composition as claimed in claim 10, which includes a quaternary ammonium compound.
 12. The composition as claimed in claim 10, which includes a salt of an amine and hydrogen chloride.
 13. The composition as claimed in claim 10, which includes a compound having the general formula:
 14. The composition as claimed in claim 10, containing 0.01 -0.05 percent by weight of the organic chloro compound.
 15. The composition as claimed in claim 10, in which the copper compound is copper naphthenate or copper octoate.
 16. The composition as claimed in claim 10, containing in addition at least one filler in an amount of 5 - 500 percent by weight calculated on the polyester resin.
 17. A process for curing unsaturated polyester resins, comprising irradiating with U.V. light the composition of claim
 10. 